Best free stand-alone software to create midi drum patterns?

Hi BB friends.
I am looking for recommendations for the best free stand-alone software to create midi drum patterns.
Please fire away.
Many thanks.

See my thread Software to create BeatBuddy (BB) beats, songs and patterns

For simple, I really like Hydrogen. Once you’ve set up a BB-compatible drumkit everything is fast and intuitive. There are two main limitations…(1) you can’t import MIDI (so it is a beat builder, not an editor) and (2) you can only export the entire song as MIDI, not a selection of the song.

Here is “BeatBuddy” Hydrogen drum kit that has been mapped to match the GM standard so it imports correctly for BeatBuddy.
https://forum.singularsound.com/t/beatbuddy-drum-kit-for-hydrogen/27438?u=aliby

Once I have made the song in Hydrogen, I delete sections in the Song Editor to only have the section I want as a part and then export that to Midi. I do that for each part, fill, transition etc.

Try this one
A lot of sounds of the BB
Easy to make 'looping, add remove
Easy to import on BB
Free
Very simple
Not complicated
MidiDrum - MIDI Drum Rhythm Generator - Free Download